[1] Sungkyunkwan Univ, Sch Med, Kangbuk Samsung Hosp, Dept Occupat & Environm Med, Seoul, South Korea
[2] Hanyang Univ, Dept Med, Grad Sch, Seoul, South Korea
[3] Kongju Natl Univ, Coll Nursing & Hlth, Dept Nursing, Gongju, South Korea
[4] St Andrews Hosp, Dept Psychiat, Inchon, South Korea